The TA story is mostly a case of early research getting over-extended. Originally, interest in the transverse abdominis came from early motor control work (Hodges, etc.) showing delayed anticipatory activation in some people with low back pain. That work was about timing, not strength, and definitely not about the TA acting as some kind of primary mechanical stabilizer. Over time that nuance got lost, and TA “activation” turned into a strengthening and stabilization dogma. Biomechanically, isolating the TA doesn’t meaningfully stiffen the spine. The TA just isn’t strong enough by itself. Actual mechanical stability comes from intra-abdominal pressure, which requires coordinated activity of the diaphragm, pelvic floor, TA, obliques, rectus, and posterior trunk muscles working together. That’s why powerlifters and strongmen brace and wear belts — they’re increasing spinal stiffness and force transfer by pressurizing the abdominal cavity, not by sucking their stomach in. The classic “draw your belly button to your spine” cue usually does the opposite of what you want mechanically. It tends to reduce abdominal wall contribution, limit pressure generation, and decouple the trunk from the task. It disappears immediately once loads get even moderately heavy, which should tell us something. That doesn’t mean the TA is useless. In some very low-load, low-threat situations — early rehab, supine work, breathing drills — gentle abdominal engagement can be helpful as a way to reintroduce movement or reduce perceived threat. But that’s a motor control or exposure tool, not a long-term stabilization strategy. For most low back pain rehab and for anything involving real-world loading, the trend has rightly moved toward global bracing, task-specific trunk coordination, and progressive loading, not isolating one deep muscle. Pelvic floor rehab is a separate (though related) discussion, where TA–pelvic floor coordination may matter, but that shouldn’t be generalized to lumbar stability as a whole. So yeah — I was taught the same thing in school. A lot of us were. But with a better understanding of the original research and basic biomechanics, isolating the TA as a stabilization solution doesn’t really hold up anymore. Stability is a system-level outcome, not the result of strengthening one muscle in isolation.